The optically active substance of epoxy alcohol (formula 1) is noted as a synthetic intermediate of medicines, pesticides, and biologically active substances.
Especially, the (-)optically active substance of 2,3-epoxy-8-methyl-1-nonanol is an important constituent of sex pheromone of Lymantria dispar L. ##STR2## Here, R.sub.1 and R.sub.2 denote straight-chain or branched alkyl groups containing 1 through 20 carbon atoms.
1. Industrial Field of the Invention
The present invention relates to the methods of preparing optically active epoxy alcohol and an intermediate prepared in the process. The objective of the invention is to provide the preparation of epoxy alcohol, which readily, selectively, and efficiently yields optically active epoxy alcohol is a useful synthetic intermediate of medicines, pesticides, biologically active substances such as sex pheromone of Lymantria dispar L.
2. Description of Prior Art
Synthesis of epoxy alcohol (formula 1) has been proposed by Katsuki K. (J.Am. Chem. Soc. 1980, vol 102; 5,974) which utilizes asymmetric epoxidation of allyl alcohol.
This methods is, however, not practical; since
(1) it requires an expensive asymmetric reducing agent; PA0 (2) the temperature is to be controlled to below -50.degree. C.; and PA0 (3) it requires dangerous agents such as t-butyl hydroperoxide.
Another known method proposed by Daniel Bianchi (tetraheron Letter, 29 (20) 2455 to 2458, 88) is to synthesize the optically active substance of epoxy alcohol (formula 1) by means of asymmetric transesterification of epoxy alcohol (formula 1) and acetates with lipase.
The method also has some drawbacks to be practical such as low optical purity and poor yield.